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1.
Angew Chem Int Ed Engl ; : e202407870, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748475

RESUMO

Converting spent lithium-ion batteries (LIBs) cathode materials into environmental catalysts has drawn more and more attention. Herein, we fabricated a Co3O4-based catalyst from spent LiCoO2 LIBs (Co3O4-LIBs) and found that the role of Al and Cu from current collectors on its performance is nonnegligible. The density functional theory calculations confirmed that the doping of Al and/or Cu upshifts the d-band center of Co. A Fenton-like reaction based on peroxymonosulfate (PMS) activation was adopted to evaluate its activity. Interestingly, Al doping strengthened chemisorption for PMS (from -2.615 eV to -2.623 eV) and shortened Co-O bond length (from 2.540 Å to 2.344 Å) between them, whereas Cu doping reduced interfacial charge-transfer resistance (from 28.347 kΩ to 6.689 kΩ) excepting for the enhancement of the above characteristics. As expected, the degradation activity toward bisphenol A of Co3O4-LIBs (0.523 min-1) was superior to that of Co3O4 prepared from commercial CoC2O4 (0.287 min-1). Simultaneously, the reasons for improved activity were further verified by comparing activity with catalysts doped Al and/or Cu into Co3O4. This work reveals the role of elements from current collectors on the performance of functional materials from spent LIBs, which is beneficial to the sustainable utilization of spent LIBs.

2.
J Hazard Mater ; 470: 134215, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38626678

RESUMO

Selective and efficient removal of thiosulfates (S2O32-) to recover high-purity and value-added thiocyanate products by fractional crystallization process is a promising route for the resource treatment of coke oven gas desulfurization wastewater. Herein, catalytic wet air oxidation (CWAO), with manganese-based oxide synthesized from spent ternary lithium-ion batteries (MnOx-LIBs), was proposed to selectively remove S2O32- from desulfurization wastewater. 98.0 % of S2O32- is selectively removed by the MnOx-LIBs CWAO system, which was 4.1 times that of the MnOx CWAO system. The synergistic effect among multiple metals from spent LIBs induces the enlarged specific surface area, increased reactive sites and formation of oxygen vacancy, promoting the adsorption and activation of O2, thereby realizing high-efficiency removal of S2O32-. The satisfactory selective removal efficiency can be maintained in the proposed system under complex environmental conditions. Notably, the proposed system is cost-effective and applicable to actual wastewater, in which 81.2 % of S2O32- is selectively removed from coke oven gas desulfurization wastewater. More importantly, compared with the typical processes, the proposed process is simpler and more environmentally-friendly. This work provides an alternative route to selectively remove S2O32- from coke oven gas desulfurization wastewater, expecting to drive the development of resource utilization of coke oven gas desulfurization wastewater.

3.
Environ Sci Technol ; 57(36): 13579-13587, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37653710

RESUMO

The traditional hydrolysis-cooling-adsorption process for coke oven gas (COG) desulfurization urgently needs to be improved because of its complex nature and high energy consumption. One promising alternative for replacing the last two steps is selective catalytic oxidation. However, most catalysts used in selective catalytic oxidation require a high temperature to achieve effective desulfurization. Herein, a robust 30Fe-MCM41 catalyst is developed for direct desulfurization at medium temperatures after hydrolysis. This catalyst exhibits excellent stability for over 300 h and a high breakthrough sulfur capacity (2327.6 mgS gcat-1). Introducing Ag into the 30Fe-MCM41 (30Fe5Ag-MCM41) catalyst further enhances the H2S removal efficiency and sulfur selectivity at 120 °C. Its outstanding performance can be attributed to the synergistic effect of Fe-Ag clusters. During H2S selective oxidation, Fe serves as the active site for H2S adsorption and dissociation, while Ag functions as the catalyst promoter, increasing Fe dispersion, reducing the oxidation capacity of the catalyst, improving the desorption capacity of sulfur, and facilitating the reaction between active oxygen species and [HS]. This process provides a potential route for enhancing COG desulfurization.


Assuntos
Coque , Sulfeto de Hidrogênio , Adsorção , Hidrogênio , Sulfetos , Temperatura
4.
Water Res ; 232: 119685, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36739661

RESUMO

Ubiquitous macromolecular natural organic matter (NOM) in wastewater seriously influences the removal of emerging small-molecule contaminants via heterogeneous advanced oxidation processes because this material covers active sites and quenches reactive oxygen species. Here, sponge-like magnetic manganese ferrite (MnFe2O4-S) with a three-dimensional hierarchical porous structure was prepared via a facile solvent-free molten method. Compared with the particle-like structure of MnFe2O4-P, the sponge-like structure of MnFe2O4-S presents an enlarged specific surface area (112.14 m2·g-1 vs. 58.73 m2·g-1) and a smaller macropore diameter (68.2-77.2 nm vs. 946.5 nm). Enlarging the specific surface area increases the exposure of active sites, and adjusting the pore size helps sieve NOM and emerging contaminants. These changes are expected to effectively improve the degradation activity and overcome interference. To confirm the superiority of the sponge-like structure, MnFe2O4-S was used to activate peroxymonosulfate (PMS) for the degradation of multiple emerging contaminants, and its ability to degrade bisphenol A with and without humic acid (HA) was compared with that of MnFe2O4-P. The degradation activity of MnFe2O4-S was 1.6 times greater than that of MnFe2O4-P. Moreover, 20 mg·L-1 HA inhibited the degradation activity of MnFe2O4-S by only 7.1%, which was much lower than that obtained for MnFe2O4-P (53.4%). In addition, the excellent performance was maintained in multiple water matrices. Notably, under lake water matrices, the degradation activity of MnFe2O4-P was inhibited by 35.6% while that of MnFe2O4-S was hardly inhibited. More importantly, the MnFe2O4-S/PMS system was also applicable to the treatment of actual wastewater and 73.0% and 90.1% of total organic carbon and chemical oxygen demand was removed from bio-treated coking wastewater containing non-biodegradable contaminants and NOM. This study provides an alternative route for the green production of high-activity porous spinel ferrites with environmental anti-interference properties.


Assuntos
Águas Residuárias , Água , Solventes , Porosidade
5.
Environ Res ; 215(Pt 2): 114299, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36096167

RESUMO

The proper disposals of spent lithium-ion batteries (LIBs) and volatile organic compounds (VOCs) both have a significant impact on the environment and human health. In this work, different morphologies of α-MnO2 catalysts are synthesized using a manganese-based compound as the precursor which is high-selectively recovered from spent lithium-ion ternary batteries. Different synthesis methods including the co-precipitation method, hydrothermal method, and impregnation method are used to prepare different morphologies of α-MnO2 catalysts and their catalytic activities of toluene oxidation are investigated. Experimental results show that MnO2-HM-140 with stacked nanorods synthesized using the hydrothermal method exhibits the best catalytic performance of toluene oxidation (T90 of 226 °C under the WHSV of 60,000 mL g-1·h-1), which could be attributed to its better redox ability at low temperature and much more abundant adsorbed oxygen species at low temperature. The adsorption abilities of toluene and the replenish rate of surface lattice oxygen can be enhanced due to the increase of oxygen vacancies on the surface of MnO2-HM-140. Furthermore, the results of in-situ DRIFTS and TD/GC-MS imply that benzoate species are the main intermediate groups and then the reaction pathway of toluene oxidation on the surface of MnO2-HM-140 is proposed.


Assuntos
Compostos de Manganês , Compostos Orgânicos Voláteis , Benzoatos , Humanos , Lítio , Manganês , Óxidos , Oxigênio , Tolueno
6.
ACS Omega ; 7(8): 6710-6720, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35252666

RESUMO

In this work, solar drying technology was applied for the deep dewatering of coal slime to save thermal energy and reduce the dust produced during the hot drying process of coal slime. Solar drying technology is used to dry coal slime to realize its resource utilization. The influence of solar radiation intensity and slime thickness is investigated on the drying process. The greater the solar radiation intensity (SRI) is, the faster the drying indoor air and coal slime are heated, and the faster the drying efficiency is. As the slime becomes thinner, the internal water diffusion resistance becomes smaller and the drying efficiency correspondingly becomes faster. In addition, to facilitate the application of coal slime drying in the actual project, the Page model is fitted and found to have a good fit for solar drying coal slime. Meanwhile, the optimal drying conditions are determined by analyzing the energy utilization under different conditions. It is found that the target moisture content of 10% is optimal for coal slime drying with the highest energy utilization. The laying thickness (L) of 1 cm has the highest solar thermal efficiency of 54.1%. More importantly, economic calculation and analysis are conducted in detail on solar drying. It is found that the cost of solar drying (¥38.59/ton) is lower than that of hot air drying (¥ 65.09/ton). Therefore, solar drying is a promising method for the drying of coal slime.

7.
J Hazard Mater ; 427: 127910, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-34863568

RESUMO

A selective separation-recovery process based on tuning organic acid was proposed to the resource recycling of spent lithium-ion batteries (LIBs) for the first time. The low-cost preparation of CoFe2O4, reuse of waste acid and recovery of Li can be realized in this process, simultaneously. Li and Co in spent LIBs can be leached efficiently using citric acid as a leaching agent, and separated effectively from leaching solution by tuning oxalic acid content. The results from the characterizations of the prepared CoFe2O4 (CoFe2O4-LIBs) show that it possesses higher ratio of Co(II)/Co(III) and Fe(II)/Fe(III), larger surface specific area and more number of acid sites in comparison with pure CoFe2O4. Besides, CoFe2O4-LIBs was used to activate peroxymonosulfate (PMS) for the degradation of bisphenol A (BPA). Interestingly, its degradation performance is superior to that of pure CoFe2O4 and the related Co-based catalysts. The excellent degradation performance can be maintained in presence of inorganic ions (e.g., Cl-, HCO3-, H2PO4- and NO3-) with high concentration or humic acid. Moreover, surface-bound SO4∙- is considered as the main reactive species for the degradation of BPA. More importantly, CoFe2O4-LIBs can be readily recycled by using an external magnet and own superior ability of regeneration.

8.
Environ Res ; 193: 110563, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33278468

RESUMO

Due to the sustainable use of wastes, cathode materials of spent lithium-ion batteries are recovered and used as transition metal precursors to prepare metal oxides catalysts for the oxidation of VOCs. In this work, a series of manganese-based and cobalt-based metal oxides are synthesized via different preparation methods. Catalytic activities of the catalysts prepared are investigated through complete oxidation of oxygenated VOCs and the physicochemical properties of optimum samples are characterized. Evaluation results indicate that MnOx (SY) (HT) sample prepared via hydrothermal method and CoOx (GS) (CP) synthesized via co-precipitation method had better performance, because they have higher specific surface area, higher concentration of active oxygen species and high-valence metal ion, as well as better low-temperature reducibility compared to the other multi-metal oxides used in the study. In addition, TD/GC-MS results imply that further oxidation of by-products requires high reaction temperature during VOCs oxidation.


Assuntos
Fontes de Energia Elétrica , Lítio , Eletrodos , Metais , Óxidos , Reciclagem
9.
J Hazard Mater ; 406: 124743, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33310331

RESUMO

In this work, manganese is selectively and efficiently recovered from spent lithium-ion batteries via advanced oxidation by using potassium permanganate and ozone, and the transition metal-doped α-MnO2 and ß-MnO2 are one-step prepared for catalytic oxidation of VOCs. The recovery rate of manganese can be approximately 100% while the recovery efficiency of cobalt, nickel, and lithium is less than 15%, 2%, and 1%, respectively. Compared with pure α-MnO2 and ß-MnO2, transition metal-doped α-MnO2 and ß-MnO2 exhibit better catalytic performance in toluene and formaldehyde removal attributed to their lower crystallinity, more defects, larger specific surface area, more oxygen vacancies, and better low-temperature redox ability. Besides, the introduction of the appropriate proportion of cobalt or nickel into MnO2 can significantly improve its catalytic activity. Furthermore, the TD/GC-MS result indicates that toluene may be oxidized in the sequence of toluene - benzyl alcohol - benzaldehyde-benzoic acid - acetic acid, 2-cyclohexen-1-one, 4-hydroxy-, cyclopent-4-ene-1,3-dione - carbon dioxide. This method provides a route for the resource utilization of spent LIBs and the synthesis of MnO2.

10.
Chemosphere ; 264(Pt 1): 128398, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33007570

RESUMO

Adsorption is a simple and efficient way for arsenic contamination purification in water, with a pressing challenge to find a cheap and efficient adsorbent. As a poorly crystalline Fe(III)-oxyhydroxy sulfate mineral, schwertmannite can be As(V) adsorbent because of its tunnel structure and low cost. However, the schwertmannite synthesized commonly by H2O2 rapid oxidation suffers from the low Fe utilization and limited As(V) adsorption capacity. In this research, the schwertmannite is synthesized by KMnO4. The results show that the Fe utilization can be improved from 40% to 56%, with the As(V) adsorption capacities double times better than those synthesized by H2O2 at pH 7 and 2. The As(V) adsorption mechanisms at different pHs and the reason for the improvement of As(V) adsorption capacity are thoroughly investigated. The FTIR and EDS images confirm that As(V) adsorption exchange with SO42- is the dominant mechanism at pH 7 and 2. At pH 11, the As(V) is mainly removed by surface complexation because the surface SO42- is exchanged by OH-. The intraparticle diffusion model fitting and XPS results further reveal that the tunnel structure built by Fe-SO4 in the KMnO4 oxidized schwertmannite is more stable, possibly resulting in the better As(V) adsorption performance.


Assuntos
Arsênio , Poluentes Químicos da Água , Purificação da Água , Adsorção , Arsênio/análise , Compostos Férricos , Peróxido de Hidrogênio , Concentração de Íons de Hidrogênio , Compostos de Ferro , Poluentes Químicos da Água/análise
11.
J Colloid Interface Sci ; 578: 229-241, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32531553

RESUMO

In this work, GdMnO3 material is successfully prepared using sol-gel method and GdMn2O5/GdMnO3 materials are in-situ generated by acid treatment. These materials are investigated and applied as catalysts for oxygenated VOC complete oxidation. The evaluation results show that GdMn2O5/GdMnO3-1.00 exhibits a remarkable increase in catalytic activity (T50% = 198 °C and T90% = 225 °C) of 2-ethoxyethanol oxidation when compared with the initial sample GdMnO3 (T50% = 223 °C and T90% = none). Characterization analyses show that acid treatment can result in the significant improvement of specific surface area from 20.502 m2·g-1 to 67.952 m2·g-1, abundant surface Mn4+ content and active oxygen, excellent reducibility at low temperature in GdMn2O5/GdMnO3-1.00 sample. In-situ DRIFTS results point out that the main functional groups such as νas(OCO), νas(COO), νs(CO) are formed in the process of 2-ethoxyethanol oxidation over GdMn2O5/GdMnO3-1.00 sample and some by-products including ethanol, 2-ethoxyethyl acetate, acetic acid, carbonic acid, 2-ethoxyethyl 2-methoxyethyl ester, ethane and 1,1'-oxybis[2-methoxy-] can be produced at a reaction temperature of 200 °C. Additionally, in-situ DRIFTS studies indicate the presence of gas-phase O2 plays a vital role in facilitating 2-ethoxyethanol deep oxidation to final products.

12.
Sci Rep ; 10(1): 10450, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32591638

RESUMO

The selectivity of a facile reductive and extractive desulfurization process was studied. In this desulfurization method, polyethylene glycol was used as the extractant, and sodium borohydride was used as the reductant. Several different simulated fuels were prepared by dissolving thiophenic sulfides, methylbenzene and hexylene in octane. The results showed that methylbenzene and olefins had different effects on different sulfur compounds during this desulfurization process. The extraction and reduction mechanisms were also explained. Four factors could affect the desulfurization performance: (1) intermolecular hydrogen bonding: (a) active O bonding with aromatic H or (b) S bonding with H atoms in hydroxide radicals, (2) "like-dissolves-like" interactions between polyethylene glycol and thiophenic sulfides, (3) the methyl steric hindrance effect and the electron density of sulfur atoms, and (4) the combination of S atoms with produced nickel boride to form active desulfurization centres. The desulfurization reaction path was also deduced according to the GC/MS results.

13.
Sci Total Environ ; 740: 139951, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32563871

RESUMO

In this work, cathode materials of spent lithium-ions manganate batteries are recovered as the precursor of manganese-based oxides catalysts and furthermore, different amount of Fe, Bi, Ce are introduced to modify their properties. A series of MnOx(MS)-X Fe, MnOx(MS)-X Bi and MnOx(MS)-X Ce samples with crystal phase of Mn5O8 are synthesized using combustion method and then the catalytic behavior and physicochemical properties of prepared catalysts are investigated. Compared to binary MnOx-5% Fe, MnOx-15% Bi and MnOx-10% Ce samples, multi MnOx(MS)-5% Fe, MnOx(MS)-15 Bi and MnOx(MS)-10% Ce catalysts display enhanced catalytic performance significantly in the removal of oxygenated VOC, which could be attributed to larger specific surface area, higher concentration of surface active oxygen species and Mn4+ ions and better reducibility at low temperature. In-situ DRIFTS results imply that main oxygen-containing functional groups such as carbonyl (-C=O), carboxyl (-COO), hydroxyl (-OH) can be observed during VOC oxidation and by comparison, it can be found that gas-phase O2 plays a crucial role in facilitating the further oxidation of by-products into CO2. In addition, TD/GC-MS results point out that the main by-products are formaldehyde; 2-propanol, 1-methoxy-; ethanol, 2-methoxy-, acetate; 2-ethoxyethyl acetate; acetic acid during VOC oxidation.

14.
Inorg Chem ; 58(20): 14275-14283, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31589423

RESUMO

Highly active samarium manganese perovskite oxides were successfully prepared by employing self-molten-polymerization, coprecipitation, sol-gel, and impregnation methods. The physicochemical properties of perovskite oxides were investigated by XRD, N2 adsorption-desorption, XPS, and H2-TPR. Their catalytic performances were compared via the catalytic oxidation of toluene. The perovskite prepared by self-molten-polymerization possessed the highest catalytic capacity, which can be ascribed to its higher oxygen adspecies concentration (Olatt/Oads = 0.53), higher surface Mn4+/Mn3+ ratio (Mn4+/Mn3+ = 0.95), and best low-temperature reducibility (H2 consumption = 0.27; below 350 °C). The most active catalyst also exhibited good cycling and long-term stability for toluene oxidation. After a multistep cycle reaction and a long-term reaction of 42 h, the toluene conversion maintained above 99.9% at 270 °C. Mechanistic study hinted that lattice oxygen was involved in toluene oxidation. The oxidation reaction was dependent on the synergism of lattice oxygen, adsorbed oxygen, and oxygen vacancies. The degradation pathway of toluene, researched by diffuse reflectance infrared Fourier transform spectroscopy and online mass spectrometry technologies, demonstrated that a series of organic byproducts existed at a relatively low temperature. This work provides an efficient and practical method for selecting highly active catalysts and for exploring the catalytic mechanism for the removal of atmospheric environmental pollution.

15.
Environ Sci Technol ; 53(23): 13868-13877, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31577132

RESUMO

Pd-Cu catalysis is combined with in situ electrolytic H2 evolution for NO3- reduction with protonated polypyrrole (PPy) as a cathode. The surface of PPy is not only beneficial for H2 evolution, but exclusive for NO3- adsorption, and thus inhibits NO3- reduction. Meanwhile, the in situ H2 generation exhibits a much higher utilization efficiency because of the smaller bubble size and higher dispersion. The Pd-Cu catalysts with the ratios of 6:1 and 4:1 exhibit the highest NO3--N removal (100%) and N2 selectivity (93-95%) after 90 min. In comparison with the results obtained with other cathode materials (Ti, Cu, Co3O4, and Fe2O3) and obtained by other researchers, the new process shows a faster NO3--N reduction rate and much higher N2 selectivity. However, the O2 generated on the anode can oxidize Cu to Cu2O that may work as the catalyst for NO3--N reduction to NH4+-N by H2, resulting in more than 60% NH4+-N generated without a proton exchange membrane. Both the PPy film and Pd-Cu catalyst exhibit good stability and there is no Cu2+ or Pd2+ in solution after reaction. Real industrial wastewater is further treated in this system, the NO3--N is reduced from 670 mg L-1 to less than 100 mg L-1 in 90 min, and only little amount of NH4+-N is generated.


Assuntos
Polímeros , Pirróis , Catálise , Eletrodos , Nitratos
16.
Inorg Chem ; 58(19): 13241-13249, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31496227

RESUMO

A series of highly defected Mn3-xFexO4 spinels with different amounts of oxygen vacancies and active metals were successfully synthesized by regulating the insertion of Fe ions into the crystal structure of Mn3O4 via self-polymerizable monomer adjustment of the molten Mn-Fe salt dispersion. The characterization of X-ray diffraction, Raman, scanning electron microscopy, X-ray photoelectron spectroscopy, and N2 adsorption-desorption showed that the doping of Fe increased the lattice defects, oxygen vacancy concentration, specific surface area, mesoporosity, and catalytic properties compared to Cu ions doping. Temperature-programmed reduction with hydrogen and oxygen pulse chemisorption tests determined that the doping level of Fe ions had an important influence on the oxygen vacancy content and the dispersion of active metals on the catalysts' surfaces. For the best Mn-dispersed and most active Mn2.4Fe0.6O4 catalyst, a long-term toluene oxidation measurement running for 120 h of uninterrupted reaction, at the low temperature of 240 °C, high humidity (relative humidity = 100%), and high weight hourly space velocity of 60000 mL·g-1·h-1, was also carried out, which indicated that the catalyst possessed high stability and endurability. Moreover, the continuous oxidation route and internal principle for toluene oxidation were also revealed by the in situ diffuse-reflectance infrared Fourier transform spectroscopy and gas chromatography-mass spectrometry techniques and deep dynamics study.

17.
J Hazard Mater ; 380: 120905, 2019 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-31349144

RESUMO

Valuable metals such as manganese, cobalt, nickel and copper are recycled from spent ternary lithium-ions batteries (LiBs) and are considered as the active metal precursor to prepare based-manganese multi oxide for VOCs oxidation. The results of characterization analysis indicate that the catalyst from spent LiBs shows larger specific surface area of 26.80 m2/g as well as abundant mesoporous structures on the surface, higher molar ratio of Mn4+/Mn3+ (0.70) and Olatt/Oads (1.68), better low-temperature reductivity and stronger intensity of weak acid sites in comparison with those of pure manganese oxides. The evaluation experiments show that the catalyst from waste exhibits more excellent catalytic performance of toluene combustion in comparison with pure manganese oxides. Furthermore, the presence of considerable amount of lithium and aluminum ions can severely weaken the catalytic activity while the co-existence of nickel, cobalt and copper ions contribute a lot to facilitate the catalytic behavior. In-situ DRIFT study implies that the introduction of lithium, aluminum, nickel, copper and cobalt into pure manganese oxides can facilitate toluene conversion to various extents, following the consecutive steps via benzyl species, benzoyl oxide species, benzaldehyde species, benzoate species and the primary intermediates are benzoate species.

18.
Artigo em Inglês | MEDLINE | ID: mdl-30818848

RESUMO

Volatile organic compounds (VOCs) emission from anthropogenic sources has becoming increasingly serious in recent decades owing to the substantial contribution to haze formation and adverse health impact. To tackle this issue, various physical and chemical techniques are applied to eliminate VOC emissions so as to reduce atmospheric pollution. Among these methods, non-thermal plasma (NTP) is receiving increasing attention for the higher removal efficiency, non-selectivity, and moderate operation, whereas the unwanted producing of NO2 and O3 remains important drawback. In this study, a dielectric barrier discharge (DBD) reactor with wedged high voltage electrode coupled CuO foam in an in plasma catalytic (IPC) system was developed to remove toluene as the target VOC. The monolith CuO foam exhibits advantages of easy installation and controllable of IPC length. The influencing factors of IPC reaction were studied. Results showed stronger and more stable plasma discharge in the presence of CuO foam in DBD reactor. Enhanced performance was observed in IPC reaction for both of toluene conversion rate and CO2 selectivity compared to the sole NTP process at the same input energy. The longer the contributed IPC length, the higher the toluene removal efficiency. The toluene degradation mechanism under IPC condition was speculated. The producing of NO2 and O3 under IPC process were effectively removed using Na2SO3 bubble absorption.


Assuntos
Poluentes Atmosféricos/química , Catálise , Cobre/química , Oxirredução , Tolueno/química , Compostos Orgânicos Voláteis/química , Eletrodos
19.
J Hazard Mater ; 362: 178-186, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30236939

RESUMO

γ-MnO2, SmMnO3, and γ-MnO2/SmMnO3 catalysts were prepared by facile methods, wherein the SmMnO3 (SMO) perovskite was synthesized through one-step calcination and the γ-MnO2/SmMnO3 was formed by an in situ growth of γ-MnO2 on the surface of SMO. These materials ware characterized by XRD, SEM-mapping, N2-adsorption, XPS and H2-TPR to investigate their textural properties. Compared with that of SMO and γ-MnO2, the γ-MnO2/SMO shows better performance for catalytic oxidation of aromatic VOCs in wet air (10 vol.%), which may be attributed to its higher surface molar ratio of lattice oxygen to adsorbed oxygen (Olatt/Oads) and better low-temperature reducibility. Besides, for γ-MnO2/SMO catalyst, a successive oxidation route and the inner principle of BETX (benzene, ethylbenzene, toluene, and o-xylene) oxidation were also revealed via various tests and a comprehension of dynamics investigation. Meanwhile, the experiments under simulated realistic exhaust conditions displayed that the γ-MnO2/SmMnO3 is also a good catalyst with high stability for aromatic VOCs oxidation, and fulfilled endurability to high humidity (20 vol.%).

20.
Nat Commun ; 9(1): 4180, 2018 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-30301939

RESUMO

The elucidation of molecular events that confer tamoxifen resistance to estrogen receptor α (ER) positive breast cancer is of major scientific and therapeutic importance. Here, we report that LEM4 overexpression renders ER+ breast cancer cells resistant to tamoxifen by activating the cyclin D-CDK4/6 axis and the ERα signaling. We show that LEM4 overexpression accelerates tumor growth. Interaction with LEM4 stabilizes CDK4 and Rb, promotes Rb phosphorylation and the G1/S phase transition. LEM4 depletion or combined tamoxifen and PD0332991 treatment significantly reverses tamoxifen resistance. Furthermore, LEM4 interacts with and stabilizes both Aurora-A and ERα, promotes Aurora-A mediated phosphorylation of ERα-Ser167, leading to increase in ERα DNA-binding and transactivation activity. Elevated levels of LEM4 correlates with poorer relapse-free survival in patients with ER+ breast cancer undergoing endocrine therapy. Thus, LEM4 represents a prognostic marker and an attractive target for breast cancer therapeutics. Functional antagonism of LEM4 could overcome tamoxifen resistance.


Assuntos
Neoplasias da Mama/patologia , Ciclina D/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Receptor alfa de Estrogênio/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Nucleares/metabolismo , Proteína do Retinoblastoma/metabolismo , Tamoxifeno/farmacologia , Animais , Aurora Quinase A/metabolismo , Neoplasias da Mama/metabolismo , Carcinogênese/efeitos dos fármacos , Carcinogênese/metabolismo , Carcinogênese/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Fase G1/efeitos dos fármacos , Humanos , Camundongos Nus , Fosforilação , Ligação Proteica/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Fase S/efeitos dos fármacos , Transdução de Sinais , Análise de Sobrevida , Ativação Transcricional/efeitos dos fármacos , Resultado do Tratamento
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